diff --git a/docs/configuration_reference/behavior_version.rst b/docs/configuration_reference/behavior_version.rst
index 9e5e1da9a..82723a408 100644
--- a/docs/configuration_reference/behavior_version.rst
+++ b/docs/configuration_reference/behavior_version.rst
@@ -23,6 +23,7 @@ Version History
 ---------------
 
 Behavior version 21 (2024-04-25)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 RF ``pad`` and TF ``PadLayer`` defaults changed: